3D Design A4 File Folder, Expandable Holds up to 2.8", It can contain up to 1000 sheets of A4 paper per plastic wallet. The sides of the file bags are made of expandable durable polymeric material. BluePower extendable folders and file wallets could help you easy to carry large books and documents. Each Envelope with a Lable Pocket and Elastic Band, Better Help you Sort Through the Various Files, Elastic Band Design for Conveniently Opening and Securing Contents, and Lets you no Longer Worry About File Loss. The see-through sleek document folder keeps contents visible and makes finding documents so easy without opening your envelopes